Plug and receptacle



J. M. ROPER PLUG AND RECEPTACLE Filed Feb. 12, 1938V i Nov. 28, 1,939.

vv v vill"1111111111111147111111114 INVENTOR JOHN M. DO/PEI? Ww/( &0.ATTORNEY Patented Nov. 28, 1939 UNITED STATES PATENT OFFICE (Grantedunder the act of March s, 1883, asA

amended April 30, 1928; 370 O. G. 757) This invention relates toa doublecontact electrical receptacle and plug especially intended for use'onaircraft, and more particularly on aircraft instrument boards, whereinthe instrument board may be provided with receptacles of this invention,and the plug of this invention may be connected thereto at desired timesfor affording a power circuit to the wires connected to the receptacle.vThere are some instruments on aircraft, particularly military aircraftof the bombing type, which are actuatable by electrical circuits, butwhere, as a safety precaution, it is desirable that the power to suchinstruments be enlely disconnected when early use of such in truments,such as operating bomb dropping tra contemplated. AWith this inventionit becomes possible to sever the power connection from the Vsource ofcurrent 4to the instrument and thus avoid. relyingV upon an ordinaryswitch which might accidentally complete the circuit to cause anundesired operation.

A further object of this invention is tn provide a receptacle includingmale contacts and a plug` including female contacts, and to providemeans whereby the female contacts of the plug will be double locked tothe male contacts of the receptacle, preventing accidental separationthereof. With the foregoing and other objects in view, the inventionconsists in the construction, combination and arrangement of partshereinafter described and illustrated in the drawing, in which,

Fig. 1 is an elevational View, partly in section,

of the plug and receptacle in interlocked relation.

Fig. 2 is a sectional view of the plug assembly.

Fig. 3 is an end view looking at the left of'Fig. 2.

Fig. 4 is a partly sectional and partly elevational vieW of thereceptacle assembly; and

Fig. 5 is an end view looking at the right of Fig. 4. v

There is shown at I0 the interlocking plug assembly II and receptacleassembly I2 constituting this invention. l

The plug assembly II consists of a housing I3 provided with appropriatebayonet slots I4 for holding it in assembled relation with the recep-ftacle I2. One end of the housing I3 is threaded as at I5 to receive acap I6 which holds a gland I1 pressed about a conduit I8, through whicheX- tends conductors I 9 whose ends 20 Aare soldered into hollow pins 2I which integrally extend from the backs of female contacts 22. 'I'hesefemale contacts 22 are placed through apertures in an insulating spacer23 and abut against the flanges 24 at the ends of apertures 25. Thefemale contacts 22 are held in the spacer 23 by aninsulat- ,is notingsleeve 26 which abuts against the shoulder 21 formed between the pins 2|and the backs of the female contacts 22, sleeve 26 being provided withrecess 28 to alignwith the outside of the pins,2I, the spacer `23 beingheld Within the end of the housing I3 by a cross-bar 3|) in a suitablypositioned recess 3| extending across the end of the spacer 23. l

The receptacle assembly I2 includes a housing 3l having a flange 32,whereby it may be suitably secured as to an instrument board. A cap 33serves for holding the receptacle `assembly in assembled position.Within the housing 3| there is placed an insulating plug member 34 inthe shape of a cylindrical disc, but having bayonet slots 35 on oppositesides thereof cooperating with bayonet pins secured through the housing'3I. .The bayonet slots 35 have one side wall 31 extending in a straightline the full thickness of the cylindrical disc 34,` while the otherwall 38 is S shaped, and thus extending partly through the cylindricaldisc, thereby providing a bayonet pin receiving recess 39.

Extending into this insulating plug member 34 are a pair of male fingercontacts 4|! which are split as at 4I, so as to make them slightlyyieldable and permit them to be inserted into the female contacts 22 ofthe plug assembly II.

The male contacts 40 terminate on the other side of the male plug member34 in hollow ends 42, within which may. be soldered the conduit wires 43extending from the conduit cable 44. An insulating spaced sleeve 45,identical with the sleeve 26, is placed about the hollowed ends 42between the insulating plug member 34, anda shouldered insulatingferrule 46 is placed withinV the cap 33 about the end of the .cable 44,the shouldered ferrule 46 being urged by the spring 41 against thesleeve 45, spring 41 abutting against an inturned flange 48 of the cap33.

In operation, the plug assembly II and the receptacle assembly I2 areeach assembled as shown in Figs. 2 and 4, with the'bayonet slot 35 ofthe 1 insulating plug member 34 in the position shown in Fig. 4, havingthe bayonet pin 38 located withlin the recess 39, being urged into suchposi- When inserting the plug it is rotated to bring the pins 50 intolocked position within the bayonet slots I4.

Simultaneously with this insertion and rotating movement the insulatingplug member 34 will, with sleeve 45, move against spring 41, therebypermitting the plug assembly II to enter a sufficient distance. Thenwhen the plug I I is rotated to lock the bayonet slots I4 on the pins50, the pin 36 will be removed from the recess 3 9 of bayonet slot 35 inreceptacle plug member 34 to a position adjacent the bayonet slot wall31, as shown in Fig. 1, so that when the plug II is locked within thereceptacle I2 the receptacle plug member 34 is released from the bayonetpin 36 and its male finger contacts 40 yieldably urged into the femalecontacts 22 to a tight contact. On disconnecting the plug II from thereceptacle I2, the plug II is first pushed, rotated, and then withdrawn,which movements will 'again bring the pin 36 back into the bayonet slotrecess 39 and thus hold the receptacle plug member 34 and its fingercontacts safely within the housing 3l.

Inasmuch as cable I8 and the plug assembly vII is connected to thesource of electrical current the .cable 44 of receptacle assembly I2 isconnected to the instrument to be operated, it is obvious that there maybe nol circuit to the cable .44, unless and until the female contacts 22have The invention described herein may be manufactured and used by orfor the Government of the United States of America for governmentalpurposes without the payment of any royalties thereon or therefor.

Having thus set forth and disclosed the nature of this invention, whatis claimed is:

In combination, an electric plug and a receptacle, said plug includingfemale contact means and said receptacle including male contact means,means unrestrictedly yieldably urging the male contact means of thereceptacle into the female contact means of the plug when the plug is incontact with the receptable, and means restricting the movement of themale contact means in the receptacle when the plug is not in contacttherewith, said last mentioned means including an insulating plug memberthrough which said male contact means is mounted, a cooperating bayonetslot means on the side of said insulating plug member and pin means onsaid receptacle, said bayonet slot means having a shoulder in saidinsulating plug member cooperating with said pin means to limit thelongitudinal movement of said insulating plug member in one positionthereof and having a through slot therein to free the said insulatingplug member for unrestricted yieldable movement in another positionthereof, and cooperating bayonet pin and slot means in said plug andsaid receptacle, whereby when said plug and receptacle are relativelyrotated when brought into contact. the insulating` plug member isrotated to the position of unrestricted yieldable movement to press themale contact means into the female contact means.

JOHN M. ROPER.

